This invention relates in general to building structures and, in particular, to an improved stairway assembly.
More specifically, without restriction to the particular use which is shown and described, this invention relates to an improved reinforced tread assembly for use in a stairway system and the like and employing a reinforced concrete tread supported by a novel technique to increase the strength of the system and to protect the tread from damage. The improved reinforced tread assembly herein disclosed provides a sturdy and lightweight structure, achieving superior results in use.
Concrete has long been a commonly used material forming the whole or part of a stairway structure. Concrete has been conventionally employed in the prior art, because it offers a sturdy and durable material providing a long life of service, while being subjected to constant pedestrian travel and various loading conditions. The utilization of concrete to form the treads and structure of stairways and the like does present several disadvantages, which cause significant difficulties to the manufacturer of the stair system as well as the installer at the job site. Concrete suffers from an inherent weakness in tensile strength requiring the use of internal reinforcing agents in the form of rods and the like to provide adequate structural integrity. An assembled steel and concrete stairway creates a relatively heavy structure in order to attain a system possessing suitable strength. Such an assembled structure is cumbersome for shipment to a construction site and difficult to erect. One technique employed to overcome the assembled weight problems of prior art stairway systems is to ship the concrete stair treads and other components separately, or alternatively, form the stairway itself at the job site by pouring unset concrete into an erected formwork. Such a solution is unsatisfactory, because it requires time consuming and uneconomic construction effort. Thus, the use of conventional concrete involves the use of a relatively heavy material for a given load capacity, which is uneconomical to ship and inconvenient to install.
In recent years, a material has been introduced to the marketplace consisting of a cement reinforced by glass fiber material and providing a lightweight, and highly strong structure. The use of such a lightweight and sturdy reinforced concrete is very desirable for adoption in stairways and the like, since the complete stairway, with treads installed, can readily be shipped from the manufacturer to the construction site. Such reinforced concrete is also advantageous for incorporation in a stairway system, since the quantity of material needed to attain a suitable degree of strength is much less in comparison to normal concrete, even when reinforced with structural elements, thus reducing deadweight. Potentially, the use of a glass fiber reinforced material as a tread of a stairway could thus be highly beneficial as a component of a stairway system. However, fiberglass concrete suffers from several problems which have prevented its previous effective utilization in stairway structures. Reinforced concrete is subject to undesirable chipping, particularly at its exposed edges such as are present in a tread member. Further, difficulty has previously been encountered in achieving an efficient and suitable attachment of the glass fiber reinforced cement tread to the stairway system by a simplified and economical technique. In addition to the foregoing problems, concrete is also subject to undesired penetration or damage under high impact or loadings which can be detrimental to its effective use. Thus, it is desirable to provide an improved system by which a fiberglass reinforced concrete tread can be utilized in a stairway system and the like such that the aforementioned problems are overcome by an economical and lightweight, sturdy construction.